1. Field of the Invention
The present invention relates to a camera having a lens barrier which protects a taking lens by covering it at the time of non-usage.
2. Description of the Related Art
A camera having a lens barrier is known. The lens barrier is for protecting a taking lens. For example, the camera having the lens barrier is provided with an opening formed in a front face of a camera body and for exposing the taking lens. This opening is uncovered by moving the lens barrier so as to cross a photographic optical path.
In a recent camera, such lens barrier is moved by a motor. When a main switch of the camera is turned on, the lens barrier is evacuated from the photographic optical path to expose the taking lens. When the switch is turned off, the lens barrier is put at the optical path to cover the taking lens. In virtue of this, the taking lens is protected when the camera is not used, for example, while the camera is carried so that it is possible to keep the taking lens in a good condition. Meanwhile, some type of a camera having the lens barrier is provided with a lens barrel which protrudes from an opening at the time of usage and is collapsed into the opening at the time of non-usage. In this type, the lens barrel is fully covered with the lens barrier when the camera is not used. Thus, unevenness of an external shape of the camera may be reduced at the time of non-usage so that it is convenient for keeping the camera. Recently, a compact camera adopting such structure increases.
As to the camera in which the lens barrier is operated by a motor, a drive speed of the motor is quickened so as not to miss a shutter chance. Owing to this, it is possible to rapidly switch the camera from the non-usage state to the usage state. By the way, in a conventional camera, when the lens barrier is closed, the motor is reversed without changing the drive speed thereof. Thus, there arises a problem in that a finger of a user is likely to be injured, since there is a possibility that the finger is caught between an edge of the opening and the lens barrier.
In view of the foregoing, it is a primary object of the present invention to provide a camera having a lens barrier in which a finger is hardly caught in the lens barrier when the lens barrier is closed, whereas the lens barrier can be rapidly opened.
It is a second object of the present invention to provide a camera having a lens barrier in which a drive speed of a motor for operating the lens barrier is easily adjusted at low cost.
In order to achieve the above and other objects, the camera according to the present invention comprises a lens barrier which is opened and closed by a motor. The lens barrier covers and uncovers an opening formed in a front face of the camera. The opening is for exposing a taking lens of the camera.
When the camera is used, the lens barrier is opened to expose the taking lens through the opening. When the camera is not used, the opening is covered with the lens barrier to protect the taking lens.
A drive speed of the motor for operating the lens barrier is controlled by a motor control unit. When the motor opens the lens barrier, the drive speed of the motor is controlled by the motor control unit so as to be faster. Thus, the lens barrier is rapidly opened. When the motor closes the lens barrier, the drive speed of the motor is controlled by the motor control unit so as to be slower. Thus, the lens barrier is closed at a slower speed in comparison with the opening speed thereof.
In a preferred embodiment, a DC motor is used as the motor. When the lens barrier is closed, the motor control unit intermittently drives the DC motor for a predetermined period so as to gradually slow down the drive speed of the DC motor.
Further, in a preferred embodiment, the opening for exposing the taking lens is formed in a camera body. A lens barrel incorporated with the taking lens is thrust out and is collapsed through this opening. The operation of the lens barrier and the movement of the lens barrel are performed by a single motor.